Mixer for cutting torches



Jan. 28, 1930. G. c. QuELcH MIXER FOR CUTTING TORCHES Filed Sept. 28,` 1928 S'imm w@ p/b Patented Jan. Z8, 1930 UNITE STATES PATENT OFFICE GEORGE C. QUELCH, OF OAKMONT, PENNSYLVANIA, ASSIGNOR TO INTERNATIONAL OXYGEN COMPANY, OF NEWARK, NEW JERSEY, .A CORPORATION OF NEW JERSEY MIXER FOR CUTTING TORCHES Application led September 28, 1928. Serial No. 309,026.

My invention refers to an improvement in the class of torches for the cutting of ferrous metals. The present invention refers more particularly to means for etfecting a more thorough mixture of the combustion gases with oxygen prior to delivery from the tip of the torch for preheating by means of the construction herein illustrated and further described.

In such torches, which are now in large and common use, a preheating flame of high temperature is first directed against the metal to be cut, and, when the combustible temperature of the metal is reached, a jet of pure oxygen under pressure is directed against the heated portion, with a corresponding continuation of the preheating flame.

Combustion of the metal, under the oxygen jet, then occurs, reducing the metal to magnetic oxide of iron, the pressure jet of oxygen forcing the oxide through and away from the narrow curf made in the metalv as the cutting action proceeds along a given line.

In torches of this general class, the device is usually provided with three supply pipes or conduits, leading to the terminal head embodying the tip, providing for the supply of hio'h pressure oxygen for cutting, low pressure oxygen, and a combustible gas for burning therewith, for preheating.

The present improvement has in view to utilize higher pressures of the combustion gases, with consequently higher resulting velocities, partly by the use of restricted passages and orifices through which the gases, especially oxygen, pass.

The general objects in view accomplished by my invention are to fix or proportion the quantity of fuel gas passing through the mixer in proportion to the pressure; to fix or proportion the quantity of oxygen passing through the mixer in proportion to the pressure; to ix or proportion the ratio of fuel v gas to oxygenon a pressure basis; to secure a adapt it for use in any cutting torch in which the mixture of oxygen and fuel gas is effected in the head of the torch or between the fuel and oxygen supply valves and the torch head.

Incidentally, the use of the invention embodied in my improved mixer, or super-mixer, adapts it for incorporation or placement in any convenient or suitable location in the torch head. A further advantage is that by its use I prevent back firing beyond the outlet of the mixer, thus avoiding any possibility of any such undesired combustion inwardly beyond the delivery point of the cutting torch.

One preferred embodiment of the invention is illustrated in the accompanying drawings, in which:

Fig. 1 is a sectional view of the head of a conventional form of cutting torch, adapted to be provided with my improved mixer, on the line I-I of Fig. 2, beyond the mixer;

Fig. 2 is a plan view of Fig. l;

Fig. 3 is a diagonal vertical section on the line III-III of Fig. 2;

Fig. i is a diagonal cross section on the line IV-IV of Fig. 3

Fig. 5 is an enlarged detail view in elevation of the mixer, detached from the head and enlarged;

Fig. 6 is a cross section on the line VI-VI of Fig. 5; y

Fig. 7 is a view similar to Fig. 5 partly in longitudinal section, showing the circulating passages and port-s.

Referring to the drawings, A is the head of a standard torch, having the usual high pressure oxygen pipe 2, a low pressure oxygen pipe 3, and a gas supply pipe l communicating with7the several corresponding passages 5, 6 and These several conduits are controlled by valves of Well known construction and function, not necessarily shown. As is generally understood in the art, the preheating mixture is effected by mixing the low pressure oxygen from port- 6 with the preheating gas, as acetylene, hydrocarbon, etc., passing from channel 7 to the delivery passages 9 surrounding the central oxygen combustion supply passage 8 of the burner tip a.

The latter may be of any suitable standard or usable construction or well known form, the head A being provided with a common annular chamber 10 surrounding the tip within the head and communicating with the mixer-furnished supply of gas and oxygen from ports 6 and 7.

My improved mixer, as shown, is mounted at one side of the head within a projecting enlargement 11 thereof, preferably made integral with the head casting, and providing a continuous channel leading inwardly to the annular chamber 10 at an angle to the general line of the several supply pipes and conduits, as in Fig. 4.

Intervening between its ends, such channel, i. e.,`the inner wall of enlargement 11, is provided with a screw-threaded mounting 12, at each side of which are the outer annular channel 13 and the inner annular channel 14 respectively. These communicate with the preheating oxygen pipe 3 by channel 6, and the gas pipe 4 by channel 7 respectively.

The jet member a is so constructed and mounted as to function in the manner generally followed by torches of the kind involved, and to deliver a preheating flame through the several channels 9 prior to combustion of the metal by the cutting oxygen through central channel 8.

The mixer, as shown, is mounted within the communicating channel 13-14 referred to, by threaded engagement with the threads 12 at the middle portion of an outer shell member 15.

Said member, as shown, is hollow at its inner end, beyond the solid shank portion 16 having the screw or bolt head 17 for tightly inserting it in position, with an intervening packing gasket 18.

Inserted centrally in the hollow portion of the mixer part way back from its delivery end is the inner tube 19 having a central bore 20 at its inner portion communicating by central port 21 with the several lateral oxygen inlet ports 22, for supply of oxygen from pipe 3 through channel 6.

At its delivery end tube 19 is provided with a very small central outlet delivery port 23, and with similar small oxygen outlet ports 24, both communicating with the central longitudinal larger channel 20, which is in constant communication with the oxygen supply from port 6.

Beyond the middle screw-threaded barrel portion 25 of tube 15 is an annular space 26 between the central tube 19 and the outer shell 15, through which passage fuel gas passes toward the delivery end of the mixer. Shell 15 is provided, between its threaded portion and the delivery end, with a series of transverse fuel gas inlet ports 27 communciating with chamber 14 and port 7 for inward supply of gas from pipe 4.

lVith the mixer constructed as illustrated and as above described, and in operative combination with the burner head and its cutting tip, the operation is as follows:

Oxygen under pressure enters the ports 22 and passes inwardly through central opening 20, from which a portion of the oxygen passes outwardly under pressure in the manner of a jet through reduced port 23, other portions of oxygen in the same manner passing laterally through ports 24 to annular passage 26. Fuel gas under pressure enters from supply pipe 4, port 7, and annular channel 14, and inwardly through ports 27. rlhe induced gas here becomes mixed with the oxygen supply from ports 24, forming a partial mixture therewith which is discharged endwise from the annular passage 26. Such mixture then combines with the central oxygen jet being discharged through reduced orifice 23, the whole mixture entering the annular channel 10.

The central orifice 23 being very small, and the oxygen passing therethrough due to its pressure being discharged at high velocity, acts as an injector to speed up or induce an increased flow of the partial mixture passing through annular chamber 26.

lVith the construction as thus made and used, higher pressures and consequently higher velocities may be acomplished, due to the comparatively small passages and orifices through which the gases pass or are discharged, so as to materially increase the functional efects of the cutting torch as above stated.

It will be understood that the proportioning of the openings and ports, the construction and arrangement of the elements and their relative location, as well as other features of the invention, may be variously changed or modified by the skilled mechanic, but that all such changes are to be understood as within the scope of the following claims.

lVhat I claim is 1. In a cutting torch, the combination with a head provided with a cutting tip and a combustion mixture chamber therefor and having a gas supply conduit and an oxygen conduit, a mixer adapted to supply said chamber consisting of a tubular member having connection with the head between the gas supply and oxygen supply openings of said conduits, said member having a tubular perforated delivery shell portion and an inner tube communicating with the oxygen supply opening beyond said connection and provided with lateral perforations and an inner endmost jet perforation.

2. In a cutting torch, the combination with a head provided with a cutting tip and a combustion mixture chamber therefor and having a gas supply conduit and an oxygen conduit, a mixer adapted to supply said chamber consisting of a tubular member having connection with the head between the gas supply and oxygen supply openings of said conduits, said member having a tubular perforated delivery shell portion and an inner tube spaced inwardly within said shell communicating with the oxygen supply opening beyond said connection and provided with lateral perforation's and an inner endmost jet perforation adapted to effect mixture of gas and oxygen between the shell and tube and to effect an induced flow of such mixture to the combustion mixture chamber of the head.

3. In a cutting torch, the combinationv with a head provided with a cutting oxygen conduit, a preheating oxygen conduit, and a gas conduit, a cutting tip having a central opening communicating with the cutting oxygen conduit and a. combustion mixture chamber in the head surrounding the tip, of a mixer communicating with the preheating oxygen and gas conduit and the mixture chamber respectively, consisting of a hollow stem having an oxygen inlet port and a gas inlet port and an interior jet nozzle annularly spaced within the stem provided with a central oxygen receiving opening at its inner end and an oxygen delivery opening at its outer end, and a lateral opening respectively.

4. A mixer for cutting torches comprising a hollow stem having a middle mounting portion, an oxygen inlet port, and an inner hollow shell portion provided with a lateral perforation, and a central hollow jet member communicating with the oxygen port and with the interior of the shell portion and provided with a terminal outlet port.

5. A mixer for cutting torches comprising a hollow stem having a middle mounting portion, an oxygen inlet port, and an inner hollow shell portion provided with a lateral perforation, and a central hollow jet member spaced Within the shell having a rear connection with the oxygen inlet port and an endmost outlet port and provided with a lateral port communicating with the interior of the shell.

In testimony whereof I hereunto affix my signature. f

GEORGE C. QUELCH. 

